Wireless Communications Involving a Fast Initial Link Setup, FILS, Discovery Frame for Network Signaling

ABSTRACT

Embodiments include methods performed by a network node in a wireless communication network. The node is part of a first BSS that is one of a plurality of BSS in a Mobility Domain (MD) that supports a Fast BSS Transition procedure. Such methods include transmitting one or more Fast Initial Link Setup Discovery (FD) frames. Each FD frame includes an identifier of the first MD, which enables receiving devices to determine, without receiving any non-FD frames from the network node, whether to associate with the network node via the Fast BSS Transition procedure. Such methods include associating with a first device through the Fast BSS procedure, wherein the first wireless communication device was previously associated with one of the BSS in the MD. Other embodiments include complementary methods performed by devices, as well as network nodes and devices configured to perform such methods.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims the benefit ofpriority from, U.S. patent application Ser. No. 14/655,273 filed on Jun.24, 2015, which is a U.S. national-stage application claiming priorityto international application PCT/SE2015/050679 filed on Jun. 11, 2015,which claims priority to U.S. Provisional Patent Application No.62/115,191 filed Feb. 12, 2015. The entire disclosures of theabove-mentioned applications are incorporated herein by reference forall purposes.

TECHNICAL FIELD

The proposed technology generally concerns wireless communications andmobility in a wireless communications network, and more specifically amethod for assisting a wireless communication device in determining anassociation procedure towards a network node in a wirelesscommunications network, and a method for determining an associationprocedure towards a network node, a method of generating a frame forwireless communication, a Fast Initial Link Setup, FILS, Discovery framefor network signaling as well as corresponding network nodes, wirelessdevices, arrangements and computer programs and computer-programproducts.

BACKGROUND

Wireless communications is growing at an ever-increasing rate, and thereis a wide range of wireless communications technologies including widerange wireless communication and local area communication technologies.

For example, Wireless Local Area Network, WLAN, technology offers abasis for wireless communications within a local area coverage. Ingeneral, the WLAN technology includes industry-specific solutions aswell as proprietary protocols, although most commercial applications arebased on well-accepted standards such as the various versions of IEEE802.11, also popularly referred to as Wi-Fi.

A WLAN is a wireless network that links two or more devices using awireless distribution method, often spread-spectrum or OFDM radio,within a limited area such as a home, school, computer laboratory, oroffice building. This gives users the ability to move around within alocal coverage area and still be connected to the network, and mayprovide a connection to the wider Internet. As mentioned, most modernWLANs are based on the IEEE 802.11 standards, usually marketed under theWi-Fi brand name.

In the particular example of IEEE 802.11, also referred to as Wi-Fi,terminology, a STAtion, STA, is a device that has the capability to usethe 802.11 protocol. For example, an STA may be a laptop, a desktop PC,PDA, access point or Wi-Fi phone. An STA may be fixed, mobile orportable. Generally in wireless networking terminology, a station,wireless client and node are often used interchangeably, with no strictdistinction existing between these terms. A station may also be referredto as transmitter or a receiver based on its transmissioncharacteristics. IEEE 802.11-2007 formally defines station as: Anydevice that contains an IEEE 802.11-conformant Media Access Control,MAC, and PHYsical layer, PHY, interface to the wireless medium.

A Basic Service Set, BSS, is a set of all stations that can communicatewith each other. More specifically, a BSS provides the basicbuilding-block of an 802.11 WLAN and is defined by an Access Point, AP,together with all associated stations, STAs.

An Access Point, AP, is a device that allows wireless communicationdevices to connect to a wired network using Wi-Fi, or related standards.

Initial Connection to a WLAN Network

When a STA connects to a WLAN network, i.e. to a WLAN AP, for the firsttime, it carries out a procedure similar to the one depicted in FIG. 1.

The authentication procedure comprises the following steps:

-   -   1 The STA receives a Beacon frame revealing, among other        parameters, the security features associated with the ESS the AP        belongs to. The format of the beacon frame as well as all the        information elements it carries are described in Chapter 8.3.3.2        of IEEE 802.11, [1];    -   2 If the STA does not receive a Beacon frame for some reason, it        may generate a Probe Request and send it to the AP. This        procedure is called active scanning and by performing it, the        STA may receive from the AP the same information as it would        have from a Beacon message;    -   3 The AP answers with Probe Response;    -   a. NOTE: The discovery procedure consists of either step 1 or        steps 2 and 3 (i.e., receiving a Beacon frame and exchanging        probe messages are mutually exclusive);    -   4 The STA sends an Open System Authentication Request;    -   5 The AP responds with an Open System Authentication Response;    -   6 The STA then sends an Association Request, indicating the        security parameters to be used later;    -   7 The AP responds with an Association Response    -   a. NOTE: The Open System Authentication does not provide any        security. The connection between the STA and the AP is secured        at a later point, by means of Authentication and Key Agreement        procedure. Nevertheless, a possible attack altering the security        parameters in the Open System Authentication message exchange        will be detected at the stage of key derivation;    -   8 At this point the Open System Authentication is completed and        the STA may communicate only with the AP—the rest of the traffic        is blocked by the port-based network control (PBNC) enforcer, as        defined in IEEE 802.1X. Some of the traffic towards external        hosts, however, may be forwarded by the AP, as in the case of        the communication with the RADIUS server;    -   9 This step is the first step of the EAP-SIM authentication RFC        4186, [2]. The AP encapsulates an EAP-Request of Type 18 (SIM)        inside an EAPOL frame, asking the STA to report its identity. In        the case when the STA is equipped with a SIM, the identity is        the IMSI, followed by the “@” sign and the home realm. It is        also possible for the STA to include an additional “1” in front        of the IMSI in order to indicate preference for the exclusive        use of EAP-SIM if other EAP methods are available (e.g.,        EAP-AKAe);    -   10 The STA responds with its identity. An example of such is:        1234580123000100@wlan.mnc048.mcc264.3gppnetwork.org (and IMSI is        in this example 234580123000100 and the preceding “1” indicates        the preference to use EAP-SIM);    -   11 The AP extracts the EAP-Response message, encapsulates it in        a RADIUS frame and forwards it to the backend AAA server. The        handling of EAP frames over RADIUS is described by the IETF in        RFC 3579, [3];    -   12 The AAA server recognizes the EAP method and sends an        EAP-Request/SIM/Start, indicating that an EAP-SIM procedure has        been initiated for that Supplicant. It also includes the list of        supported SIM versions in the message as described in Chapter        10.2 of RFC 4186, [2];    -   13 The AP relays the EAP-Request/SIM/Start message to the STA;    -   14 The STA responds with EAP-Response/SIM/Start message, which        carries a random number (NONCE_MT) carried in the AT_NONCE_MT        attribute (a randomly selected number), as well as the selected        EAP-SIM version (AT_SELECTED_VERSION);    -   15 The AP forwards the EAP-Response/SIM/Start to the AAA server;    -   16 The AAA server obtains the GSM triplet (RAND, SRES and Kc)        from the HLR/AuC and derives the keying material as specified in        Chapter 7 of RFC 4186, [2]. The GSM triplet consists of:    -   a. RAND—a 128-bit random number, generated by the Authentication        Center (an entity within the GSM core network, used to        authenticate subscribers at the point of initial attach) when a        subscriber authentication is requested. Its use is for the        derivation of the Signed Response (SRES) and the Kc;    -   b. SRES—a 32-bit variable, the expected response from the mobile        station/STA after it has been challenged with the RAND;    -   c. Kc—a 64-bit ciphering key, used to encipher and decipher data        transmitted between the STA and the AP;    -   17 The AAA generates an EAP-Request/SIM/Challenge message,        including RAND challenges and message authentication code        attribute (AT_MAC). The AT_MAC derivation is based on the RAND        and Kc values;    -   18 The AP forwards the EAP-Request/SIM/Challenge message to the        STA;    -   19 The STA feeds the received RAND into the GSM algorithms        running on the SIM and the output is a copy of the AT_MAC and a        SRES value. The first thing for the STA to do is to check        whether the AT_MAC value received by the AAA (relayed by the AP)        and the one generated by the SIM match. If so the STA continues        with the authentication, otherwise it responds with an        EAP-Response/SIM/Client-Error message. The second thing is to        derive a new AT_MAC, based on the generated SRES;    -   20 The new AT_MAC is sent to the AAA server (via the AP) in an        EAP-Response/SIM/Challenge message;    -   21 The AP forwards the EAP-Response/SIM/Challenge to the AAA        server;    -   22 The AAA server verifies the new AT_MAC value that the STA has        just sent. If the verification is successful, it sends an        EAP-Success message to the AP. The message also carries keying        material—Pairwise Master Key (PMK). The PMK is intended for the        AP only and it is not forwarded to the STA (the STA may derive        the same key autonomously since it is based on the Kc, which the        SIM in the STA may compute based on the RAND);    -   23 The AP forwards the EAP-Success message to the STA and stores        the PMK for the following Four-way handshake;    -   24 The AP uses the PMK to generate an Authenticator nonce        (ANonce);    -   25 The ANonce value is sent to the STA in an EAPOL-Key message;    -   26 Using the received ANonce (together with the SNonce and the        PMK), the STA constructs the Pairwise Temporal Key (PTK);    -   27 The STA sends an EAPOL-Key message to the AP, including a        Supplicant nonce (SNonce) and a message integrity code (MIC);    -   28 The AP uses the ANonce, SNonce and the PMK to construct the        PTK. The AP also uses the MIC in order to verify that the STA        has computed the correct and fresh key. Furthermore, the AP also        generates and installs a Group Temporal Key (GTK, which is used        exclusively for the encryption and decryption of broadcast and        multicast traffic;    -   29 The AP sends to the STA an encrypted GTK, a sequence number        to use for the next broadcast message and an instruction to        install the PTK (the message is integrity protected by another        MIC);    -   30 The STA responds with an acknowledgement message;    -   31 The STA installs both the PTK and the GTK and as of this        point uses them to encrypt and decrypt all communication;    -   32 The AP also installs the PTK;    -   33 The 802.1X Controlled Port is now open and the STA may        communicate with other network hosts besides the AP.

As may be understood from the above, the authentication procedure may belengthy and involve a lot of signalling. STAs that move around in thenetwork will perform re-associations many times. Thus there is room forimprovement of the association and re-association procedures.

SUMMARY

It is an object to improve the performance of a wireless communicationsnetwork.

It is another object to provide a method for assisting a wirelesscommunication device in determining an association procedure towards anetwork node in a wireless communications network.

It is also an object to provide a method for determining an associationprocedure towards a network node.

Another object is to provide a method of generating a frame for wirelesscommunication.

Yet another object is to provide an improved Fast Initial Link Setup,FILS, Discovery frame for network signaling in a wireless communicationnetwork.

Still another object is to provide a network node configured to assist awireless communication device in determining an association proceduretowards the network node.

It is also an object to provide a wireless device configured todetermine an association procedure towards a network node.

Another object is to provide an arrangement configured to generate aframe for wireless communications.

Yet another object is to provide corresponding computer programs andcomputer-program products.

Still another object is to provide a network node for assisting awireless communication device in determining an association proceduretowards the network node.

It is also an object to provide a wireless device for determining anassociation procedure towards a network node.

Another object is to provide an arrangement for generating a frame forwireless communication.

These and other objects are met by at least one of the embodiments ofthe proposed technology.

According to a first aspect, there is provided a method performed by anetwork node for assisting a wireless communication device indetermining an association procedure towards the network node in awireless communications network. The method comprises:

sending information to the wireless communication device in a FastInitial Link Setup, FILS, Discovery frame, which information relates toa Mobility Domain to which the network node belongs, to enable thewireless communication device to determine whether to associate with thenetwork node through a full authentication procedure or through areduced authentication procedure.

According to a second aspect, there is provided a method performed by awireless communication device for determining an association proceduretowards a network node in a wireless communications network. The methodcomprises:

receiving information from the network node in a Fast Initial LinkSetup, FILS, Discovery frame, which information relates to a MobilityDomain to which the network node belongs, and

determining whether to associate with the network node through a fullauthentication procedure or through a reduced authentication procedure,based on the information relating to the Mobility Domain.

According to a third aspect, there is provided a method of generating aframe for wireless communication, wherein the method comprises:

including Mobility Domain information in a Fast Initial Link Setup,FILS, Discovery frame for network signaling in a wireless communicationnetwork.

According to a fourth aspect, there is provided a Fast Initial LinkSetup, FILS, Discovery frame for network signaling in a wirelesscommunication network, wherein the FILS Discovery frame includesMobility Domain information.

According to a fifth aspect, there is provided a network node configuredto assist a wireless communication device in determining an associationprocedure towards the network node in a wireless communications network.The network node is configured to send information to the wirelesscommunication device in a Fast Initial Link Setup, FILS, Discoveryframe, which information relates to a Mobility Domain to which thenetwork node belongs, to enable the wireless communication device todetermine whether to associate with the network node through a fullauthentication procedure or through a reduced authentication procedure.

According to a sixth aspect, there is provided a wireless deviceconfigured to determine an association procedure towards a network nodein a wireless communications network. The wireless device is configuredto receive information from the network node in a Fast Initial LinkSetup, FILS, Discovery frame, which information relates to a MobilityDomain to which the network node belongs. The wireless device is alsoconfigured to determine whether to associate with the network nodethrough a full authentication procedure or through a reducedauthentication procedure, based on the information relating to theMobility Domain.

According to a seventh aspect, there is provided an arrangementconfigured to generate a frame for wireless communications, wherein thearrangement is configured to include Mobility Domain information in aFast Initial Link Setup, FILS, Discovery frame for network signaling ina wireless communication network.

According to an eight aspect, there is provided a computer programcomprising instructions, which when executed by at least one processor,cause the at least one processor to prepare a Fast Initial Link Setup,FILS, Discovery frame for transmission from a network node to a wirelessdevice by including information relating to a Mobility Domain to whichthe network node belongs in the FILS Discovery frame, to enable thewireless communication device to determine whether to associate with thenetwork node through a full authentication procedure or through areduced authentication procedure.

According to a ninth aspect, there is provided a computer programcomprising instructions, which when executed by at least one processor,cause the at least one processor to determine whether to associate awireless communication device with a network node through a fullauthentication procedure or through a reduced authentication procedure,based on information received from the network node in a Fast InitialLink Setup, FILS, Discovery frame, which information relates to aMobility Domain to which the network node belongs.

According to a tenth aspect, there is provided a computer programcomprising instructions, which when executed by at least one processor,cause the at least one processor to generate a frame for wirelesscommunication by including Mobility Domain information in a Fast InitialLink Setup, FILS, Discovery frame.

According to an eleventh aspect, there is provided a computer-programproduct comprising a computer-readable medium having stored thereon acomputer program as defined above.

According to a twelfth aspect, there is provided a network node forassisting a wireless communication device in determining an associationprocedure towards the network node in a wireless communications network.The network node comprises a preparation module for preparing a FastInitial Link Setup, FILS, Discovery frame for transmission to a wirelessdevice by including information relating to a Mobility Domain to whichthe network node belongs, to enable the wireless communication device todetermine whether to associate with the network node through a fullauthentication procedure or through a reduced authentication procedure.

According to a thirteenth aspect, there is provided a wireless devicefor determining an association procedure towards a network node in awireless communications network. The wireless device comprises adetermining module for determining whether to associate the wirelesscommunication device with the network node through a full authenticationprocedure or through a reduced authentication procedure, based oninformation received from the network node in a Fast Initial Link Setup,FILS, Discovery frame, which information relates to a Mobility Domain towhich the network node belongs.

According to a fourteenth aspect, there is provided an arrangement forgenerating a frame for wireless communication. The arrangement comprisesa frame generating module for generating a Fast Initial Link Setup,FILS, Discovery frame by including Mobility Domain information in theFILS Discovery frame.

An advantage of the proposed technology is that the improved FILSDiscovery frame enables receiving devices such as wireless terminals orstations to determine whether a reduced and thus faster authenticationprocedure can be used, hence improving the overall association orre-association procedure.

Other advantages will be appreciated when reading the detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments, together with further objects and advantages thereof,may best be understood by making reference to the following descriptiontaken together with the accompanying drawings, in which:

FIG. 1 is a schematic diagram illustrating an example of a conventionalWLAN authentication procedure.

FIG. 2 is a schematic diagram illustrating an example of a networktopology for supporting Fast BSS Transition, FT, in a WLAN network.

FIG. 3 is a schematic diagram illustrating an example of the format of aMobility Domain Element.

FIG. 4 is a schematic diagram illustrating an example of the FTCapability and Policy field.

FIG. 5 is a schematic diagram illustrating an example of the processflow for a Fast BSS Transition, FT, procedure.

FIG. 6 is a schematic diagram illustrating an example of the frameformat of a conventional FILS Discovery Frame.

FIG. 7 is a combined signaling and action diagram illustrating anexample of signaling and corresponding actions.

FIG. 8 is a schematic diagram illustrating an example of relevant partsof a wireless communication network.

FIG. 9 is a schematic flow diagram illustrating an example of a methodfor assisting a wireless communication device in determining anassociation procedure towards the network node in a wirelesscommunications network according to an embodiment.

FIG. 10 is a schematic block diagram illustrating implementationexamples of a network node.

FIG. 11 is a schematic flow diagram illustrating an example of a methodfor determining an association procedure towards a network node in awireless communications network according to an embodiment.

FIG. 12 is a schematic block diagram illustrating implementationexamples of a wireless communication device according to an embodiment.

FIG. 13 is a schematic diagram illustrating an example of an improvedFILS Discovery frame according to an embodiment.

FIG. 14 is a schematic diagram illustrating an example of a vendorspecific element in a FILS Discovery frame including Mobility Domaininformation.

FIG. 15 is a schematic flow diagram illustrating an example of a methodfor generating a frame for wireless communication according to anembodiment.

FIG. 16 is a schematic block diagram illustrating implementationexamples of an arrangement according to an embodiment.

FIG. 17 is a schematic diagram illustrating an example of a computerimplementation according to an embodiment.

DETAILED DESCRIPTION

Throughout the drawings, the same reference designations are used forsimilar or corresponding elements.

For a better understanding of the proposed technology, it may be usefulwith a brief overview and analysis with reference to the particularnon-limiting context of a Wireless Local Area Network, WLAN.

As part of developing embodiments herein, a problem will first beidentified and discussed. Wi-Fi will be used as a non-limiting exampleof a wireless communications network in which the problem may arise. Theterms Wi-Fi and WLAN are used interchangeably herein.

WLAN Fast BSS Transition

When an STA is performing transition between APs, it does notnecessarily carry the full authentication procedure as described above.One of the 802.11 standard amendments, namely IEEE 802.11r, now part ofIEEE 802.11-2012, introduces a Fast BSS Transition, FT, managementfeature to support seamless handovers between APs. In that way, when anSTA performs a handover between different APs that are part of the samemobility domain, it will not need to perform a complete authenticationwith the target AP, but only renew the over-the-air encryption. Anexample of the network topology for the Fast BSS Transition scenario isdepicted in FIG. 2.

The mobility domain information is advertised by the different APseither by broadcast, i.e. in the Beacon frame, or unicast signaling,i.e. in the Probe Response and/or Association/Re-Association Responseframes. The exact information element, in which the mobility domaininformation is comprised in is called the Mobility Domain Element, MDE,and its formatting is depicted in FIG. 3.

Furthermore, the Mobility Domain IDentifier, MDID, is the actual fieldthat carries the unique, i.e. locally unique for a particular networkprovider and not globally unique, identifier of the mobility domain.

When an STA performs a fast-BSS transition to another AP, it will notrun a complete re-authentication, but will only renew the over-the-airencryption, deriving a fresh PTK with the target AP. A STA thatinitiates a Fast BSS Transitions procedure is referred to as Fast BSSTransition Originator, FTO. The complete flow for the procedure is shownin FIG. 5. Note that this call only depicts the case when the Fast BSStransition happens in a Robust Secure Network, RSN; for other scenarios,the process calls look differently.

The detailed explanation of the steps is as follows:

-   -   1 The STA (FTO) is associated and authenticated to APA (the        source AP), successfully transmitting encrypted data;    -   2 The STA determines that a transition to another AP (APB, the        target AP) should be performed. The decision may be based on        different metrics, including signal strength, noise level, etc.;    -   3 The STA sends an Authentication Request to APB, indicating the        Fast Transition Authentication Algorithm (FTAA), the RSN Element        (RSNE), the Mobility Domain Element (MDE) and the Fast BSS        Transition Element (FTE) which carries the Supplicant Nonce        (SNonce) and the R0KH-ID. The R0KH-ID associates with the        PMK-R0;    -   4 (OPTIONAL) If APB does not have the PMK-R1, indicated by the        STA, it may request it from the R0KH, usually the Access Point        Controller (AC). The R0KH from which the key may be fetched is        identified by R0KHName, as indicated by the STA in the        Authentication Request message from Step 3;    -   5 (OPTIONAL) The R0KH (AC) provides the PMK-R1;    -   6 APB then responds with an Authentication Response, indicating        the FTAA, the RSNE, the MDE and the FTE, which in this case        carries in addition to the SNonce and R0KH-ID also the        Authentication Nonce, ANonce, and the R1 KH-ID, associated with        the PMK-R1 key. The STA and the APB both compute the new PTK,        based on the SNonce, ANonce, PMK-R1 and PMKR1 Name;    -   7 The STA then re-associates with APB within the allowed        Re-association Deadline Time, sending a Re-association Request;    -   8 APB responds with Re-association Response;    -   9 The 802.1X controlled port is unblocked and the STA may        successfully transmit encrypted data with APB;

Fast Initial Link Setup (FILS)

An amendment to the IEEE 802.11 standard, the Fast Initial Link Setup,FILS, introduces a new broadcast frame, the FILS Discovery frame, alsoreferred to as the FD frame, which is sent more often than the Beaconframe. While the Beacon frame is usually sent every 100 ms, the FD framemay be sent as often as every 20 or even 10 ms. A goal of having the FDframe is to improve and speed up the initial association procedure.However, due to the higher periodicity of the FD frame, its contents arekept to a bare minimum in order to not degrade the over the airperformance by introducing too much management traffic. The content ofthe FD frame is shown in FIG. 6. Examples of extended FILS frames can befound in references [4, 5].

The inventors have recognized the possibility of integrating Fast BSSTransition and FILS, and pin-pointed certain opportunities related tothese procedures. Once an STA has carried out an initial association toa certain mobility domain, as per the procedure depicted in FIG. 1, ithas the opportunity to carry out a Fast BSS Transition, as per theprocedure depicted in FIG. 5, when it wants to re-associate with anotherAP, e.g. a target AP, in the same mobility domain as the AP to which theSTA has initially associated to, e.g. a source AP. By performing a FastBSS Transition, the STA significantly reduces the interruption time andnetwork signaling associated with the AP-to-AP transition.

Currently, a FILS STA may attempt association with a FILS AP afterhaving received as little as a FD frame as shown in FIG. 7. However, inorder for the STA to be able to carry a re-association, it needs to beable to recognize whether the target AP is part of the same mobilitydomain as the source AP. Since the FD frame sent by a FILS AP does notcarry any information with regards to the mobility domain to which saidAP belong, the FILS STA has no way of knowing whether or not it mayperform a Fast BSS Transition to this AP. In this sense, the FILS STAmay need to carry a regular FILS association as opposed to a Fast BSSTransition re-association. This will in some cases generate extranetwork signaling and impact negatively the transition time.

Embodiments herein amend the information broadcasted by a FILS APcarried in a FILS Discovery frame with information about a mobilitydomain to which said AP belongs to. In this way, a FILS STA will befully aware of the mobility domain to which that AP belongs to afterhaving received as little as one FD frame.

According to an aspect of embodiments herein, there is provided a methodperformed by a network node for assisting a wireless communicationdevice in determining an association procedure towards the network nodein a wireless communications network.

The network node sends information to the wireless communication devicein a Fast Initial Link Setup, FILS, Discovery frame, which informationrelates to a mobility domain to which the network node belongs, andwhich information enables the wireless communication device to determinewhether to associate with the network node through a full authenticationprocedure or through a reduced authentication procedure. Reference canbe made to step 901 in FIG. 9.

According to another aspect of embodiments herein, there is provided anetwork node configured to perform the method above, as will bedescribed in detail later on.

According to yet another aspect of embodiments herein, there is provideda method performed by a wireless communication device for determining anassociation procedure towards a network node in a wirelesscommunications network.

The wireless communication device receives information from the networknode in a Fast Initial Link Setup, FILS, Discovery frame, whichinformation relates to a mobility domain to which the network nodebelongs. Reference can be made to step 1101 in FIG. 11.

The wireless communication device determines whether to associate withthe network node through a full authentication procedure or through areduced authentication procedure, based on the information relating tothe mobility domain. Reference can be made to step 1102 in FIG. 11.

According to still another aspect of embodiments herein, there isprovided a wireless communication device configured to perform themethod above, as will be described in detail later on.

According to an aspect of embodiments herein, there is provided a methodof generating a frame for wireless communication. The method comprisesincluding Mobility Domain information in a Fast Initial Link Setup,FILS, Discovery frame for network signaling in a wireless communicationnetwork. Reference can be made to step 1301 in FIG. 15.

According to another aspect of embodiments herein, there is provided anarrangement configured to perform the method above, as will be describedin detail later on.

Since the FILS Discovery frame carries information related to themobility domain to which the network node belongs, the wirelesscommunication device is able to discover whether the reducedauthentication procedure is possible or not in a faster and lessresource demanding way. This improves the association and/orre-association procedure which results in an improved performance of thewireless communications network.

The wireless communication device significantly reduces the interruptiontime and the network signaling associated with the re-associationprocedure, for example when transitioning between a source network nodeand target network node.

By way of example, the Mobility Domain information includes a MobilityDomain Identifier, MDID, or a Mobility Domain Element, MDE, or arepresentation thereof.

For example, the Mobility Domain information may include a hashed valueof the MDID or MDE.

The Mobility Domain information may for example be introduced as aninformation element in the FILS Discovery frame.

Optionally, the Mobility Domain information is introduced as a vendorspecific element in the FILS Discovery frame.

Alternatively, the Mobility Domain information is included as a field ina FILS Indication element, which is part of the FILS Discovery frame.

In a particular example, the Mobility Domain information enables awireless communication device to determine whether or not to associatewith a network node through a Fast Basic Service Set, BSS, Transitionprocedure, based on the information about the mobility domain.

In an optional embodiment, the method for assisting a wirelesscommunication device in determining an association procedure alsocomprises associating with the wireless communication device through areduced authentication procedure. Reference can be made to the optional(dashed lines) step 902 in FIG. 9.

In another optional embodiment, the method for determining anassociation procedure also comprises associating with the network nodethrough a reduced authentication procedure. Reference can be made to theoptional (dashed lines) step 1103 in FIG. 11.

In a particular example, the reduced authentication procedure comprisesactions of a Fast BSS Transition procedure.

By way of example, a mobility domain may be regarded as a set of BasicService Sets, BSSs, within the same Extended Service Set, ESS, thatsupport Fast BSS Transition, FT, between themselves and that areidentified by the set's Mobility Domain Identifier, MDID. Accordingly, aMDID is an example of an identifier that identifies a Mobility Domain.

An FT initial mobility domain association may be seen as a firstassociation or first re-association procedure within a mobility domain,during which a STA indicates its intention to use the FT procedures.

According to an aspect, there is provided a Fast Initial Link Setup,FILS, Discovery frame for network signaling in a wireless communicationnetwork, wherein the FILS Discovery frame includes Mobility Domaininformation.

At least one aspect of the proposed technology thus relates to theprocedure of generating a Fast Initial Link Setup, FILS, Discovery frameincluding Mobility Domain information and/or the exchange of such aframe between a network node and a wireless communication device, e.g.to enable the wireless communication device to determine whether toassociate with the network node through a full authentication procedureor through a reduced authentication procedure.

Embodiments herein may be implemented in one or more wirelesscommunications networks whereof FIG. 8 depicts relevant parts of awireless communication network 800. The wireless communications network800 may for example be a WLAN, such as Wi-Fi. Wi-Fi will hereafter beused to exemplify the embodiments.

The wireless communications network 800 comprises a plurality of APsand/or other network nodes. More specifically, the wirelesscommunications network 800 comprises a network node 811, also referredto as a target network node herein. The wireless communications network800 may comprise a second network node 812, also referred to as a sourcenetwork node herein.

The term “network node” may correspond to any type of radio network nodeor any network node, which communicates with at least a radio networknode. For example, the network node 811 may be an Access Point, AP, BaseStation, Wi-Fi AP, base station router, or any other network unitcapable of communicating with a wireless communication device.

Network nodes, such as base stations and Wi-Fi APs, communicate over theair or radio interface operating on radio frequencies with wirelesscommunication devices within range of the network nodes. The wirelesscommunication devices transmit data over the radio interface to networknodes, such base stations and Wi-Fi APs, in uplink, UL, transmissions,and network nodes, such as Wi-Fi APs and base stations, transmit dataover an air or radio interface to the wireless communication devices indownlink, DL, transmissions.

In embodiments herein a wireless communication device 830, also referredto as a STA, is within communication range of the network node 811, buthas not yet started an authentication procedure towards the network node811.

In some embodiments, the wireless communication device 830 is in atransition process between the second network node 812 and the firstnetwork node 811.

The wireless communication device 830 may further be e.g. a mobileterminal or a wireless terminal, User Equipment, UE, a mobile phone, acomputer such as e.g. a laptop, a Personal Digital Assistants, PDAs, ora tablet computer, sometimes referred to as a surf plate, with wirelesscapability, target device, device to device UE, MTC UE or UE capable ofmachine to machine communication, iPad, smart phone, Laptop EmbeddedEquipment, LEE, Laptop Mounted Equipment, LME, USB dongles etc. or anyother radio network units capable to communicate over a radio link in awireless communications network.

Please note the term User Equipment used herein also covers otherwireless communication devices such as machine to machine, M2M, devices,even though they do not have any user.

It will be appreciated that the methods and devices described herein canbe combined and re-arranged in a variety of ways.

For example, embodiments may be implemented in hardware, or in softwarefor execution by suitable processing circuitry, or a combinationthereof.

The steps, functions, procedures, modules and/or blocks described hereinmay be implemented in hardware using any conventional technology, suchas discrete circuit or integrated circuit technology, including bothgeneral-purpose electronic circuitry and application-specific circuitry.

Particular examples include one or more suitably configured digitalsignal processors and other known electronic circuits, e.g. discretelogic gates interconnected to perform a specialized function, orApplication Specific Integrated Circuits, ASICs.

Alternatively, at least some of the steps, functions, procedures,modules and/or blocks described herein may be implemented in softwaresuch as a computer program for execution by suitable processingcircuitry such as one or more processors or processing units.

Examples of processing circuitry includes, but is not limited to, one ormore microprocessors, one or more Digital Signal Processors, DSPs, oneor more Central Processing Units, CPUs, video acceleration hardware,and/or any suitable programmable logic circuitry such as one or moreField Programmable Gate Arrays, FPGAs, or one or more Programmable LogicControllers, PLCs.

It should also be understood that it may be possible to re-use thegeneral processing capabilities of any conventional device or unit inwhich the proposed technology is implemented. It may also be possible tore-use existing software, e.g. by reprogramming of the existing softwareor by adding new software components.

In the following sections, methods and implementation examples fordetermining or assisting in determining an association procedure towardsthe network node 811 in the wireless communications network 800 will beillustrated in more detail by a number of exemplary embodiments. Thefollowing embodiments will be described using Wi-Fi as an example andthe network node 811 will be an AP.

It should be noted that the following embodiments are not mutuallyexclusive. Components from one embodiment may be tacitly assumed to bepresent in another embodiment and it will be obvious to a person skilledin the art how those components may be used in the other exemplaryembodiments.

In the following, embodiments related to the network node will bedescribed.

According to an aspect, there is provided a network node configured toassist a wireless communication device in determining an associationprocedure towards the network node in a wireless communications network.

The network node is configured to send information to the wirelesscommunication device in a Fast Initial Link Setup, FILS, Discoveryframe, which information relates to a Mobility Domain to which thenetwork node belongs, to enable the wireless communication device todetermine whether to associate with the network node through a fullauthentication procedure or through a reduced authentication procedure.By way of example, the network node may be configured to send MobilityDomain information including a Mobility Domain Identifier, MDID, or aMobility Domain Element, MDE, or a representation thereof.

For example, the network node may be configured to send Mobility Domaininformation as an information element in the FILS Discovery frame.

In a particular example, the network node is configured to send MobilityDomain information to enable the wireless communication device todetermine whether or not to associate with the network node through aFast Basic Service Set, BSS, Transition procedure, based on theinformation about the mobility domain.

In an optional embodiment, the network node may be configured associatewith the wireless communications device through a reduced authenticationprocedure.

As an example, the network node may be configured associate with thewireless communications device through a Fast Basic Service Set, BSS,Transition procedure.

Illustrative examples of the network node 811 embodiments are describedwith reference to FIGS. 9 and 10.

According to an aspect of embodiments herein, there is provided a methodperformed by the network node 811 for assisting the wirelesscommunication device 830 in determining an association procedure towardsthe network node 811 in the wireless communications network 800.

The network node 811 may:

-   -   send 901 in a Fast Initial Link Setup, FILS, Discovery frame,        information to the wireless communication device, which        information relates to a mobility domain to which the network        node belongs. The information enables the wireless communication        device to determine whether or not to associate with the network        node through a Fast Basic Service Set, BSS, Transition        procedure, based on the information about the mobility domain,        and    -   associate (optional) 902 with the wireless communications device        830 through a reduced authentication procedure. The reduced        authentication procedure may comprise the actions described        above in relation to the WLAN Fast BSS Transition.

In a particular example, the network node 811 comprises a processor 1080and a memory 1090, the memory comprising instructions executable by theprocessor, whereby the processor is operative to assist the wirelesscommunication device in determining an association procedure towards thenetwork node.

The action in step 901 may be performed by means such as a sendingmodule 1010 in the network node 811. The sending module 1010 may beimplemented by any one or more out of a transmitter and a processor 1080in the network node 811.

The action in step 902 may be performed by means such as an associatingmodule 1020 in the network node 811. The associating module 1020 may beimplemented by the processor 1080 in the network node 811.

In the following, embodiments related to the wireless communicationdevice will be described.

According to an aspect, there is provided a wireless device configuredto determine an association procedure towards a network node in awireless communications network.

The wireless device is configured to receive information from thenetwork node in a Fast Initial Link Setup, FILS, Discovery frame, whichinformation relates to a Mobility Domain to which the network nodebelongs.

The wireless device is also configured to determine whether to associatewith the network node through a full authentication procedure or througha reduced authentication procedure, based on the information relating tothe Mobility Domain.

By way of example, the wireless device may be configured to receiveMobility Domain information including a Mobility Domain Identifier,MDID, or a Mobility Domain Element, MDE, or a representation thereof.

For example, the wireless device may be configured to receive MobilityDomain information as an information element in the FILS Discoveryframe.

In a particular example, the wireless device is configured to receiveMobility Domain information to enable the wireless communication deviceto determine whether or not to associate with the network node through aFast Basic Service Set, BSS, Transition procedure, based on theinformation about the mobility domain.

In an optional embodiment, the wireless device is configured toassociate with the network node through a reduced authenticationprocedure.

For example, the wireless device may be configured to associate with thenetwork node through a Fast Basic Service Set, BSS, Transitionprocedure.

Illustrative examples of the wireless communication device 830embodiments are described with reference to FIGS. 11 and 12.

According to an aspect of embodiments herein, there is provided a methodperformed by the wireless communication device 830 for determining anassociation procedure towards the network node 811 in the wirelesscommunications network 800.

The wireless communication device 830 may:

-   -   receive 1101 an information about a mobility domain to which the        network node belongs in a Fast Initial Link Setup, FILS,        Discovery frame from the network node 811;    -   determine 1102 whether or not to associate with the network node        811 through a Fast Basic Service Set, BSS, Transition procedure,        based on the information about the mobility domain; and    -   associate (optional) 1103 with the network node 811 through a        reduced authentication procedure. The reduced authentication        procedure may comprise the actions described above in relation        to the WLAN Fast BSS Transition.

In a particular example, the wireless device 830 comprises a processor1280 and a memory 1290, the memory comprising instructions executable bythe processor, whereby the processor is operative to determine anassociation procedure towards a network node.

The action in step 1101 may be performed by means such as a receivingmodule 1210 in the wireless communication device 830. The receivingmodule 710 may be implemented by any one or more out of a transmitterand a processor 1280 in the wireless communication device 830.

The action in step 1102 may be performed by means such as a determiningmodule 1220 in the wireless communication device 830. The determiningmodule 1220 may be implemented by the processor 1280 in the wirelesscommunication device 830.

The action in step 1103 may be performed by means such as an associatingmodule 1230 in the network node 811. The associating module 1230 may beimplemented by the processor 1280 in the network node 811.

Embodiments herein may be performed in the network node 811. The networknode 811 may comprise the modules mentioned above and depicted in FIG.10 for handling the connection.

Embodiments herein may be performed in the wireless communication device830. The wireless communication device 830 may comprise the modulesmentioned above and depicted in FIG. 12 for handling the connection.

In the following, embodiments related to an arrangement configured todetermine a frame for wireless communication will be described.

According to an aspect, there is provided an arrangement configured togenerate a frame for wireless communication. The arrangement isconfigured to include Mobility Domain information in a Fast Initial LinkSetup, FILS, Discovery frame for network signaling in a wirelesscommunication network.

By way of example, the arrangement is configured to include a MobilityDomain Identifier, MDID, or a Mobility Domain Element, MDE, or arepresentation thereof in the FILS Discovery frame.

For example, the arrangement may be configured to introduce the MobilityDomain information as an information element in the FILS Discoveryframe.

In a particular example, the Mobility Domain information enables awireless communication device to determine whether or not to associatewith a network node through a Fast Basic Service Set, BSS, Transitionprocedure, based on the information about the mobility domain.

Illustrative examples of an arrangement are described with reference toFIGS. 15 and 16.

According to an aspect of embodiments herein, there is provided a methodof generating a frame for wireless communication.

The arrangement 1500 may:

-   -   include 1301 Mobility Domain information in a Fast Initial Link        Setup, FILS, Discovery frame for network signaling in a wireless        communication network.

In a particular example, the arrangement 1500 comprises a processor 1580and a memory 1590, the memory comprising instructions executable by theprocessor, whereby the processor is operative to generate a FILSDiscovery frame.

The action in step 1301 may be performed by means such as a framegenerating module 1510 in the arrangement 1500. The frame generatingmodule 1510 may for example be implemented by the processor 1580.

With reference once again to FIG. 10, it should be understood that theprocessor 1080 and the memory 1090 of the network node 811 may beregarded as an arrangement equivalent to the one described in connectionwith FIG. 16 above.

The flow diagrams presented herein may be regarded as computer flowdiagrams, when performed by one or more processors. A correspondingnetwork node, wireless device or similar arrangement may thus be definedas a group of function modules, where each step performed by theprocessor corresponds to a function module. The computer programresiding in memory may thus be organized as appropriate function modulesconfigured to perform, when executed by the processor, at least part ofthe steps and/or tasks described herein.

With reference once again to FIG. 10, there is provided a network nodefor assisting a wireless communication device in determining anassociation procedure towards the network node in a wirelesscommunications network. The network node 811 comprises a preparationmodule 1005 for preparing a Fast Initial Link Setup, FILS, Discoveryframe for transmission to a wireless device by including informationrelating to a Mobility Domain to which the network node belongs, toenable the wireless communication device to determine whether toassociate with the network node through a full authentication procedureor through a reduced authentication procedure.

With reference once again to FIG. 12, there is provided a wirelessdevice for determining an association procedure towards a network nodein a wireless communications network. The wireless device 830 comprisesa determining module 1220 for determining whether to associate thewireless communication device with the network node through a fullauthentication procedure or through a reduced authentication procedure,based on information received from the network node in a Fast InitialLink Setup, FILS, Discovery frame, which information relates to aMobility Domain to which the network node belongs.

With reference once again to FIG. 16, there is provided an arrangementfor generating a frame for wireless communication. The arrangement 1500comprises a frame generating module 1510 for generating a Fast InitialLink Setup, FILS, Discovery frame by including Mobility Domaininformation in the FILS Discovery frame.

Alternatively, the function modules are implemented predominantly byhardware modules, or alternatively by hardware, with suitableinterconnections between relevant modules. Particular examples includeone or more suitably configured digital signal processors and otherknown electronic circuits, e.g. discrete logic gates interconnected toperform a specialized function, and/or Application Specific IntegratedCircuits, ASICs, as previously mentioned. Other examples of usablehardware include input/output, I/O, circuitry and/or circuitry forreceiving and/or sending signals. The extent of software versus hardwareis purely implementation selection.

Some embodiments will now be described in more detail.

Embodiment 1

In one embodiment, mobility domain information is included in the FILSDiscovery, FD, frame. One option is for the mobility domain informationto be introduced as a new information element in the FILS Discoveryframe. An example of a resulting FILS Discovery frame is shown in FIG.13.

Accordingly, with reference to the example of FIG. 13, there is provideda Fast Initial Link Setup, FILS, Discovery frame 1400 for networksignaling in a wireless communication network, wherein the FILSDiscovery frame includes Mobility Domain information 1401.

Another option is to introduce the mobility domain information as avendor specific element in the FILS Discovery frame.

In this case, the vendor specific element may be formatted according tothe WFA's instructions and policies for formatting of vendor specificelements introduced in Wi-Fi Alliance programs. An example of an elementformatting is shown in FIG. 14.

The fields in FIG. 14 have the following meaning:

-   -   The Element ID is a 1-octet field whose value is set to 221, the        value for vendor specific information elements.    -   The Length field is a 1-octet field that indicates the length of        the Mobility Domain information field plus the length of the OI        and Type fields.    -   The OI is a 3-octet field. As used by the Wi-Fi Alliance, the        content of the OI field is set to the value 0x50 6F 9A.    -   The Type field is a 1-octet field set to the value 0x10.    -   The Mobility Domain information field carries information        regarding the mobility domain to which a certain FILS AP        belongs. Several options of the exact information are given in        the later embodiments.

Embodiment 2

In another embodiment, related to embodiment 1, the mobility domaininformation is the complete Mobility Domain Element, MDE. This wouldimply that the FD frame would include the MDE as another element in thelist of currently present elements. An alternative to this is for themobility domain information to carry only the Mobility DomainIdentifier, MDID, field, which is one of the fields contained in theMDE. This would imply that the FD frame may include the MDID as anotherfield or element to the list of currently existing fields and elements.In the latter proposal, there are only 2 octets added to the FD frame asopposed to 5 octets if the entire MDE is included.

Embodiment 3

In another embodiment, related to embodiment 1 and 2, the mobilitydomain information which is added to the FD frame is a hashed value ofeither the MDE or the MDID, as per the two options described inembodiment 2.

A hash function is any function that may be used to map digital data ofarbitrary size to digital data of fixed size. The values returned by ahash function are called hash values, hash codes, hash sums, or simplyhashes.

There are several benefits of using a hashed value and one of them isthe reduction in the size of the MDE and MDID in the hashing procedure.The reduced size implies a smaller amount of information that is addedto the FD frame and eventually transmitted over the air. This furtherimproves the performance of the network node 811 and the wirelesscommunication device 830.

Embodiment 4

In another embodiment, related to embodiment 1, the mobility domaininformation is included as a new field in the FILS Indication element.The FILS information element is part of the FD frame. Also in this casethere are several options available in terms of which information toinclude. In one option, the MDE will be included in the FILS Indicationelement. In another option, the MDID only will be included in the FILSIndication element. Furthermore, instead of including the entire MDE orMDID, there is a possibility to include hashed versions of any of them.

Since the FILS Discovery frame carries information about the mobilitydomain to which a FILS AP belongs, the wireless communication device830, such as a FILS STA, is able to discover whether Fast BSS Transitionto the network node 811, such as a FILS AP, is possible or not. Thisimproves the association and/or re-association procedure between thewireless communication device 830 and the network node 811.

As already mentioned, embodiments herein may be implemented through oneor more processors, such as the processor 1080 in the network node 811depicted in FIG. 10, and the processor 1280 in the wirelesscommunication device 830 depicted in FIG. 12 together with computerprogram code for performing the functions and actions of the embodimentsherein. The program code mentioned above may also be provided as acomputer program product, for instance in the form of a data carriercarrying computer program code for performing the embodiments hereinwhen being loaded into the network node 811 and the UE 830. One suchcarrier may be in the form of a CD ROM disc. It is however feasible withother data carriers such as a memory stick. The computer program codemay furthermore be provided as program code on a server and downloadedto the network node 811 and wireless communication device 830.

Thus, the methods according to the embodiments described herein for thenetwork node 811 and the wireless communication device 830 may beimplemented by means of a computer program product, comprisinginstructions, i.e., software code portions, which, when executed on atleast one processor, cause the at least one processor to carry out theactions described herein, as performed by the network node 811 andwireless communication device 830.

The computer program product may be stored on a computer-readablestorage medium. The computer-readable storage medium, having storedthere on the computer program, may comprise the instructions which, whenexecuted on at least one processor, cause the at least one processor tocarry out the actions described herein, as performed by the network node811 and the wireless communication device 830. In some embodiments, thecomputer-readable storage medium may be a non-transitorycomputer-readable storage medium.

The network node 811 and the wireless communication device 830 mayfurther each comprise a memory 1090, 1290, comprising one or more memoryunits. The memory 1090, 1290 is arranged to be used to store obtainedinformation such as information in Information Elements, informationrelated to mobility domain, identities and applications etc. to performthe methods herein when being executed in the network node 811, and thewireless communication device 830.

Those skilled in the art will also appreciate that the different modulesdescribed above may refer to a combination of analog and digitalcircuits, and/or one or more processors configured with software and/orfirmware, e.g. stored in the memory, that when executed by the one ormore processors, such as the processors in the network node 811 and thewireless communication device 830 perform as described above. One ormore of these processors, as well as the other digital hardware, may beincluded in an Application-Specific Integrated Circuit, ASIC, or severalprocessors and various digital hardware may be distributed among severalseparate components, whether individually packaged or assembled into aSystem-on-a-Chip, SoC.

FIG. 17 is a schematic diagram illustrating an example of a computerimplementation according to an embodiment.

In this particular example, at least some of the steps, functions,procedures, modules and/or blocks described herein are implemented in acomputer program 1625; 1635, which is loaded from an external carrier1630 into the memory 1620 for execution by processing circuitryincluding one or more processors 1610. The processor(s) 1610 and memory1620 are interconnected to each other to enable normal softwareexecution. An optional input/output device may also be interconnected tothe processor(s) and/or the memory to enable input and/or output ofrelevant data such as input parameter(s) and/or resulting outputparameter(s).

The term ‘processor’ should be interpreted in a general sense as anysystem or device capable of executing program code or computer programinstructions to perform a particular processing, determining orcomputing task.

The processing circuitry including one or more processors is thusconfigured to perform, when executing the computer program, well-definedprocessing tasks such as those described herein.

The processing circuitry does not have to be dedicated to only executethe above-described steps, functions, procedure and/or blocks, but mayalso execute other tasks.

In a particular example, there is provided a computer program comprisinginstructions, which when executed by at least one processor, cause theat least one processor to prepare a Fast Initial Link Setup, FILS,Discovery frame for transmission from a network node to a wirelessdevice by including information relating to a Mobility Domain to whichthe network node belongs in the FILS Discovery frame, to enable thewireless communication device to determine whether to associate with thenetwork node through a full authentication procedure or through areduced authentication procedure.

In another example, there is provided a computer program comprisinginstructions, which when executed by at least one processor, cause theat least one processor to determine whether to associate a wirelesscommunication device with a network node through a full authenticationprocedure or through a reduced authentication procedure, based oninformation received from the network node in a Fast Initial Link Setup,FILS, Discovery frame, which information relates to a Mobility Domain towhich the network node belongs.

In yet another example, there is provided a computer program comprisinginstructions, which when executed by at least one processor, cause theat least one processor to generate a frame for wireless communication byincluding Mobility Domain information in a Fast Initial Link Setup,FILS, Discovery frame.

The proposed technology also provides a carrier comprising any of thecomputer programs described herein, wherein the carrier is one of anelectronic signal, an optical signal, an electromagnetic signal, amagnetic signal, an electric signal, a radio signal, a microwave signal,or a computer-readable storage medium.

By way of example, the software or computer program 1625; 1635 may berealized as a computer program product, which is normally carried orstored on a computer-readable medium 1620; 1630, in particular anon-volatile medium. The computer-readable medium may include one ormore removable or non-removable memory devices including, but notlimited to a Read-Only Memory, ROM, a Random Access Memory, RAM, aCompact Disc, CD, a Digital Versatile Disc, DVD, a Blu-ray disc, aUniversal Serial Bus, USB, memory, a Hard Disk Drive, HDD, storagedevice, a flash memory, a magnetic tape, or any other conventionalmemory device.

For example, the computer program may thus be loaded from an externalcarrier 1630 into a computer-internal carrier such as the operatingmemory 1620 of a computer or equivalent processing device for executionby the processor(s) 1610 thereof. When using the word “comprise” or“comprising” it shall be interpreted as non- limiting, i.e. meaning“consist at least of”.

The embodiments herein are not limited to the above described preferredembodiments. Various alternatives, modifications and equivalents may beused. Therefore, the above embodiments should not be taken as limitingthe scope.

1. A method performed by a network node in a wireless communicationnetwork, the network node being part of a first basic service set (BSS)that is one of a plurality of BSS in a Mobility Domain (MD) thatsupports a Fast BSS Transition procedure, the method comprising:transmitting one or more Fast Initial Link Setup Discovery (FD) frames,wherein: each FD frame includes an identifier of the MD, and theidentifier enables receiving wireless communication devices todetermine, without receiving any non-FD frames from the network node,whether to associate with the network node via the Fast BSS Transitionprocedure; and associating with a first wireless communication devicethrough the Fast BSS procedure, wherein the first wireless communicationdevice was previously associated with one of the BSS in the MD.
 2. Themethod of claim 1, wherein: the method further comprises associatingwith a second wireless communication device through a fullauthentication procedure; and the second wireless communication devicewas not previously associated with any of the BSS in the MD.
 3. Themethod of claim 1, wherein: the method further comprises transmitting aplurality of beacon frames; and transmitting the one or more FD framescomprises transmitting a plurality of the FD frames between eachsuccessive pair of the beacon frames.
 4. The method of claim 1, whereinassociating with the first wireless communication device through theFast BSS procedure comprises: receiving, from the first wirelesscommunication device, a first request including the identifier of the MDthat is included in the one or more FD frames; transmitting, to thefirst wireless communication device, a first response including theidentifier of the MD and information usable to derive an encryption keyfor secure communication between the network node and the first wirelesscommunication device; and receiving a second request, from the firstwireless communication device, within a Reassociation Deadline Timeafter receiving the first request.
 5. The method of claim 1, wherein theidentifier of the MD is included in the FD frame, in either a hashed oran unhashed format, as one of the following: as a field of an existingFD frame element; as a separate FD frame element; or as part of aseparate MD Element (MDE), in the FD frame, that also includes a FastTransition (FT) Capability and Policy field.
 6. A method, performed by awireless communication device, for associating with a network node in awireless communications network, the method comprising: receiving, fromthe network node, one or more Fast Initial Link Setup Discovery (FD)frames, wherein: each FD frame includes an identifier of a MobilityDomain (MD) that supports a Fast BSS Transition procedure, and the MDincludes a plurality of basic service set (BSS) including a first BSSassociated with the network node; without receiving any non-FD framesfrom the network node, determining whether to associate with the networknode via the Fast BSS Transition procedure, based on the identifier ofthe MD and on a second BSS to which the wireless communication device iscurrently associated; and associating with the network node through theFast BSS procedure, based on determining that the second BSS is one ofthe BSS in the MD.
 7. The method of claim 6, further comprisingassociating with the network node through a full authenticationprocedure, based on determining that the second BSS is not one of theBSS in the MD.
 8. The method of claim 6, wherein receiving the one ormore FD frames comprises receiving a plurality of the FD frames prior todetecting a beacon frame transmitted by the network node.
 9. The methodof claim 6, wherein associating with the network node through the FastBSS procedure comprises: transmitting, to the network node, a firstrequest including the identifier of the MD received in the one or moreFD frames; receiving, from the network node, a first response includingthe identifier of the MD and information usable to derive an encryptionkey for secure communication between the network node and the wirelesscommunication device; and transmitting a second request, to the networknode, within a Reassociation Deadline Time after transmitting the firstrequest.
 10. The method of claim 6, wherein the identifier of the MD isincluded in the FD frame, in either a hashed or an unhashed format, asone of the following: as a field of an existing FD frame element; as aseparate FD frame element; or as part of a separate MD Element (MDE), inthe FD frame, that also includes a Fast Transition (FT) Capability andPolicy field.
 11. A network node in a wireless communication network,the network node being part of a first basic service set (BSS) that isone of a plurality of BSS in a Mobility Domain (MD) that supports a FastBSS Transition procedure, the network node comprising: a transceivercircuit; and a processing circuit coupled to the transceiver circuit,whereby the processing circuit and the transceiver circuit are operableto: transmit one or more Fast Initial Link Setup Discovery (FD) frames,wherein: each FD frame includes an identifier of the MD, and theidentifier enables receiving wireless communication devices todetermine, without receiving any non-FD frames from the network node,whether to associate with the network node via the Fast BSS Transitionprocedure; and associate with a first wireless communication devicethrough the Fast BSS procedure, wherein the first wireless communicationdevice was previously associated with one of the BSS in the MD.
 12. Thenetwork node of claim 11, wherein: the processing circuit and thetransceiver circuit are further operable to associate with a secondwireless communication device through a full authentication procedure;and the second wireless communication device was not previouslyassociated with any of the BSS in the first MD.
 13. The network node ofclaim 11, wherein the processing circuit and the transceiver circuit arefurther operable to: transmit a plurality of beacon frames, and transmita plurality of the FD frames between each successive pair of the beaconframes.
 14. The network node of claim 11, wherein the processing circuitand the transceiver circuit are operable to associate with the firstwireless communication device through the Fast BSS procedure by:receiving, from the first wireless communication device, a first requestincluding the identifier of the MD included in the one or more FDframes; transmitting, to the first wireless communication device, afirst response including the identifier of the MD and information usableto derive an encryption key for secure communication between the networknode and the first wireless communication device; and receiving a secondrequest, from the first wireless communication device, within aReassociation Deadline Time after receiving the first request.
 15. Thenetwork node of claim 11, wherein the identifier of the MD is includedin the FD frame, in either a hashed or an unhashed format, as one of thefollowing: as a field of an existing FD frame element; as a separate FDframe element; or as part of a separate MD Element (MDE), in the FDframe, that also includes a Fast Transition (FT) Capability and Policyfield.
 16. A wireless communication device configured to configured toassociate with a network node in a wireless communications network, thewireless communication device comprising: a transceiver circuit; and aprocessing circuit coupled to the transceiver circuit, whereby theprocessing circuit and the transceiver circuit are operable to: receive,from the network node, one or more Fast Initial Link Setup Discovery(FD) frames, wherein: each FD frame includes an identifier of a MobilityDomain (MD) that supports a Fast BSS Transition procedure, and the MDincludes a plurality of basic service set (BSS) including a first BSSassociated with the network node; without receiving any non-FD framesfrom the network node, determine whether to associate with the networknode via the Fast BSS Transition procedure, based on the identifier ofthe MD and on a second BSS to which the wireless communication device iscurrently associated; and associate with the network node through theFast BSS procedure, based on determining that the second BSS is one ofthe BSS in the MD.
 17. The wireless communication device of claim 16,wherein the processing circuit and the transceiver circuit are furtheroperable to associate with the network node through a fullauthentication procedure, based on determining that the second BSS isnot one of the BSS in the MD.
 18. The wireless communication device ofclaim 16, wherein the processing circuit and the transceiver circuit areoperable to receive a plurality of the FD frames prior to detecting abeacon frame transmitted by the network node.
 19. The wirelesscommunication device of claim 16, wherein the processing circuit and thetransceiver circuit are operable to associate with the network nodethrough the Fast BSS procedure by: transmitting, to the network node, afirst request including the identifier of the MD received in the one ormore FD frames; receiving, from the network node, a first responseincluding the identifier of the MD and information usable to derive anencryption key for secure communication between the network node and thewireless communication device; and transmitting a second request, to thenetwork node, within a Reassociation Deadline Time after transmittingthe first request.
 20. The wireless device of claim 16, wherein theidentifier of the MD is included in the FD frame, in either a hashed oran unhashed format, as one of the following: as a field of an existingFD frame element; as a separate FD frame element; or as part of aseparate MD Element (MDE), in the FD frame, that also includes a FastTransition (FT) Capability and Policy field.
 21. A non-transitory,computer-readable medium storing computer-executable instructions that,when executed by a processor of a network node in a wirelesscommunication network, configure the network node to perform operationscorresponding to the method of claim
 1. 22. A non-transitory,computer-readable medium storing computer-executable instructions that,when executed by a processor of a wireless communication device,configure the wireless communication device to perform operationscorresponding to the method of claim 6.